README web version of /home/usg/OPS/MTS/readme_xml/readme_79505500

Principal Investigator Email Address

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petitjean@iap.fr
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Estimated Total Execution Time (hours, including overheads)

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5 hours
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General Description

Our on-going GMRT  survey (300 hrs of telescope time) for 21-cm absorbers
 at 
1.10 < z < 1.45 has uncovered 5 new systems out of 16 candidates searched
 till now.  
One of the systems, at z = 1.36086 towards J2340-0037, shows a very narrow ( 1 km/s)
 
and strong 21-cm absorption line. A public KECK spectrum with low SNR=15 and resolution
R=35000 shows a well detached SiII component at the redshift of the 21-cm line.
 
By comparing the position of the 21cm absorption to that of the corresponding absorption
 
in the UV, it is possible to constrain the variation of the constant x = alpha^2
 G_p\mu. 
The existing KECK data itself provides already a good constraint from a single system
 
at this redshift Delta x/x = (1.27+_2.96)x10^{-6}.
The UVES data of much better SNR and resolution will improve the constraint 
by a factor of 3 and provide an independent discriminator for the ongoing 
controversy about the variation of alpha.

Waiver Requests

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No Waiver Request was submitted
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Critical Observing Condition Constraints

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None
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Time-Critical Aspects

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Object at alpha=23h00.
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Special Execution Requirements

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None
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Special Calibration Information

A ThAr exposure is appended to each science exposure.

ToO Information

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None
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ToO Activators List

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None
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Is this a Pre-imaging run ?

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false
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Pre-imaging Requirements

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None
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Source(s) of Pre-imaging

---(Empty)---

Pre-imaging sources not listed above

---(Empty)---

Do all your OBs comply with the instrument-specific requirements listed on the instrument-specific Phase 2 web page ?

If this is a pre-imaging run, did you select PRE-IMAGING for the Observing Category for each Observing Template ?

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N/A
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Do all your finding charts comply with both the general and instrument-specific Phase 2 Web Pages ?

If you submitted OBs for standard stars, did you specify the magnitude and spectral type of all standard stars in the OBs ?

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N/A
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Have you included OBs for any calibrations that you need but which are not part of the Calibration Plan ?

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N/A
```

If you are observing Moving Targets, have you attached suitable ephemeris files to your OBs?

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N/A
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If you have preferences which OBs should be executed first, did you make use of the User Priority field in the OBs ?

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N/A
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If this is a run that requires coordinated observations with other facilities, did you give proper instructions in the Time-Critical Aspects Section ?

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N/A
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If you need secondary guiding, are there suitable objects within 30 arcsec from your target ?

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N/A
```

Last creation of page: Tue Oct 6 15:40:20 2009
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